Developers - don't you just love them? Well not Google Wallet at any rate. Without the support of developers and the APIs that they need Google Wallet is a niche player.

Hidden in all the launch hype is an interesting detail - Google Wallet expects to succeed without the support of the wider developer community. Other payment services, notably PayPal have been going out of their way to entice programmers to get down and dirty with their APIs - but not Google.

Wallet is of course a bit different. You take your NFC supporting mobile phone and download Wallet. Next you pair it with your existing credit card or with a special Google prepaid virtual card. Next to pay for anything you simply hold the phone near the reader. The transaction goes ahead even if you don't have a network connection i.e. it is local between you and the reader and for security you have to enter a four digit PIN to the phone.

Of course this begs the question of "what reader?"

The answer is that the reader is any existing MasterCard PayPass reader and Google claims that there are over 120,000 in use already. If you don't have a PayPass reader then you can get one for free with a $100 processing credit - after that you have to pay a transaction fee.

The whole process is sweetened for the user by the automatic use of any special offers and automatic management of loyalty points and other "come ons".

It all sounds good but for it to become a ubiquitous payment system you would think it needs apps and apps mean developers. However Google seem to have left developers out of the equation. No pre-release APIs, Toolkits, SDKs or samples. No documentation in fact. There is a sort of distant promise that some sort of API but try and find out anything about it and you will be disappointed.

In addition the actual secure hardware and associated APIs are very firmly closed except to "authorized programs". Even so Google claims that Wallet is an open system in that it can use many payment sources, They also promise an API that will allow banks to "integrate payment instruments" and manage offers, loyalty programs etc.

Notice that there is no mention of an open payment API.

What so I have all my credit cards loaded into Google Wallet and now I'm browsing a website. Time comes to check out - oh wait you mean I can't pay for this stuff with Google Wallet?

What sort of wallet is this?

A wallet that can pay using near field comms is cool. A wallet that can ONLY pay using near field comms is lame.

Without an open payment API Google Wallet occupies an interesting niche.